arch/ia64/sn/pci/pcibr/pcibr_ate.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights reserved.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <asm/sn/sn_sal.h>
  11 #include <asm/sn/pcibr_provider.h>
  12 #include <asm/sn/pcibus_provider_defs.h>
  13 #include <asm/sn/pcidev.h>
  14
  15 int pcibr_invalidate_ate;       /* by default don't invalidate ATE on free */
  16
  17 /*
  18  * mark_ate: Mark the ate as either free or inuse.
  19  */
  20 static void mark_ate(struct ate_resource *ate_resource, int start, int number,
  21                      u64 value)
  22 {
  23         u64 *ate = ate_resource->ate;
  24         int index;
  25         int length = 0;
  26
  27         for (index = start; length < number; index++, length++)
  28                 ate[index] = value;
  29 }
  30
  31 /*
  32  * find_free_ate:  Find the first free ate index starting from the given
  33  *                 index for the desired consecutive count.
  34  */
  35 static int find_free_ate(struct ate_resource *ate_resource, int start,
  36                          int count)
  37 {
  38         u64 *ate = ate_resource->ate;
  39         int index;
  40         int start_free;
  41
  42         for (index = start; index < ate_resource->num_ate;) {
  43                 if (!ate[index]) {
  44                         int i;
  45                         int free;
  46                         free = 0;
  47                         start_free = index;     /* Found start free ate */
  48                         for (i = start_free; i < ate_resource->num_ate; i++) {
  49                                 if (!ate[i]) {  /* This is free */
  50                                         if (++free == count)
  51                                                 return start_free;
  52                                 } else {
  53                                         index = i + 1;
  54                                         break;
  55                                 }
  56                         }
  57                 } else
  58                         index++;        /* Try next ate */
  59         }
  60
  61         return -1;
  62 }
  63
  64 /*
  65  * free_ate_resource:  Free the requested number of ATEs.
  66  */
  67 static inline void free_ate_resource(struct ate_resource *ate_resource,
  68                                      int start)
  69 {
  70         mark_ate(ate_resource, start, ate_resource->ate[start], 0);
  71         if ((ate_resource->lowest_free_index > start) ||
  72             (ate_resource->lowest_free_index < 0))
  73                 ate_resource->lowest_free_index = start;
  74 }
  75
  76 /*
  77  * alloc_ate_resource:  Allocate the requested number of ATEs.
  78  */
  79 static inline int alloc_ate_resource(struct ate_resource *ate_resource,
  80                                      int ate_needed)
  81 {
  82         int start_index;
  83
  84         /*
  85          * Check for ate exhaustion.
  86          */
  87         if (ate_resource->lowest_free_index < 0)
  88                 return -1;
  89
  90         /*
  91          * Find the required number of free consecutive ates.
  92          */
  93         start_index =
  94             find_free_ate(ate_resource, ate_resource->lowest_free_index,
  95                           ate_needed);
  96         if (start_index >= 0)
  97                 mark_ate(ate_resource, start_index, ate_needed, ate_needed);
  98
  99         ate_resource->lowest_free_index =
 100             find_free_ate(ate_resource, ate_resource->lowest_free_index, 1);
 101
 102         return start_index;
 103 }
 104
 105 /*
 106  * Allocate "count" contiguous Bridge Address Translation Entries
 107  * on the specified bridge to be used for PCI to XTALK mappings.
 108  * Indices in rm map range from 1..num_entries.  Indices returned
 109  * to caller range from 0..num_entries-1.
 110  *
 111  * Return the start index on success, -1 on failure.
 112  */
 113 int pcibr_ate_alloc(struct pcibus_info *pcibus_info, int count)
 114 {
 115         int status;
 116         unsigned long flags;
 117
 118         spin_lock_irqsave(&pcibus_info->pbi_lock, flags);
 119         status = alloc_ate_resource(&pcibus_info->pbi_int_ate_resource, count);
 120         spin_unlock_irqrestore(&pcibus_info->pbi_lock, flags);
 121
 122         return status;
 123 }
 124
 125 /*
 126  * Setup an Address Translation Entry as specified.  Use either the Bridge
 127  * internal maps or the external map RAM, as appropriate.
 128  */
 129 static inline u64 __iomem *pcibr_ate_addr(struct pcibus_info *pcibus_info,
 130                                        int ate_index)
 131 {
 132         if (ate_index < pcibus_info->pbi_int_ate_size) {
 133                 return pcireg_int_ate_addr(pcibus_info, ate_index);
 134         }
 135         panic("pcibr_ate_addr: invalid ate_index 0x%x", ate_index);
 136 }
 137
 138 /*
 139  * Update the ate.
 140  */
 141 void inline
 142 ate_write(struct pcibus_info *pcibus_info, int ate_index, int count,
 143           volatile u64 ate)
 144 {
 145         while (count-- > 0) {
 146                 if (ate_index < pcibus_info->pbi_int_ate_size) {
 147                         pcireg_int_ate_set(pcibus_info, ate_index, ate);
 148                 } else {
 149                         panic("ate_write: invalid ate_index 0x%x", ate_index);
 150                 }
 151                 ate_index++;
 152                 ate += IOPGSIZE;
 153         }
 154
 155         pcireg_tflush_get(pcibus_info); /* wait until Bridge PIO complete */
 156 }
 157
 158 void pcibr_ate_free(struct pcibus_info *pcibus_info, int index)
 159 {
 160
 161         volatile u64 ate;
 162         int count;
 163         unsigned long flags;
 164
 165         if (pcibr_invalidate_ate) {
 166                 /* For debugging purposes, clear the valid bit in the ATE */
 167                 ate = *pcibr_ate_addr(pcibus_info, index);
 168                 count = pcibus_info->pbi_int_ate_resource.ate[index];
 169                 ate_write(pcibus_info, index, count, (ate & ~PCI32_ATE_V));
 170         }
 171
 172         spin_lock_irqsave(&pcibus_info->pbi_lock, flags);
 173         free_ate_resource(&pcibus_info->pbi_int_ate_resource, index);
 174         spin_unlock_irqrestore(&pcibus_info->pbi_lock, flags);
 175 }